1. Field of the Invention
This invention relates to systems for filtering and purifying air drawn into a substantially enclosed environment, and particularly to such systems intended for improvement of indoor air quality in residential, commercial, medical and industrial environments by removing contaminants from the air.
2. General Background
Airborne contaminants are of various sizes and forms and include both inert and organic substances as well as biologically active contaminants such as pollens, bacteria and viruses. The spectrum of contaminants ranges from the angstrom size of individual molecules, as in the case of hydrocarbons and inert gases such as radon, to the particulates that range into micron size. Persons with respiratory issues who desire to breathe cleaner air normally seek relief from such contaminants by utilization or application of various filtration systems designed specifically to remove designated types of contaminants from the air that they breathe. It is commonly assumed that the removal of airborne particulates will alleviate upper respiratory tract irritation, whereas the true sources of such irritation may sometimes be hydrocarbons or other volatile organic compounds. Although health experts agree on the profound effect that these volatile airborne contaminants have upon the respiratory tract, their main focus has been on assaying the damage to health and finding the sources of the contaminants rather than finding solutions to the problem.
Although prior to my invention various types of mechanical and absorption filtering systems were known for removing particulate, hydrocarbon and other volatile organic compounds from air, it has not been so widely understood that these different technologies can be applied synergistically in a sequential process for filtering and purifying the air to obtain superior overall performance and efficiency as compared to applying these technologies separately or nonsequentially. By subjecting a flow of air to a sequence of mechanical and absorption filtering stages, my invention achieves effective and economical removal of the entire range of airborne contaminants, including particulates and volatile organic compounds, for residential, commercial, medical and industrial applications where cost and effectiveness are critical concerns.